As compared to other areas of infectious disease, antiviral therapy has rapidly advanced during the last decades. However, despite intense efforts by pharmaceutical companies, relatively few antiviral drugs are available, in contrast to the plethora of antibiotics in clinical use. There are two main reasons for the limited use of antiviral agents: (1) most drug candidates have proven too toxic in humans, and (2) the widespread use of some antiviral agents has led to emergence of drug-resistant virus strains, particularly in immunocompromised patients.
Due to the above constraints in use of antiviral agents, and following surprising results obtained and presented herewith, the present invention is meant to provide novel compositions which prevent, and/or provide, symptomatic relief of lesions and sores associated with a herpes virus, and which compositions do not require the presence of a nucleoside analogue or any other antiviral agent now in use.
More specifically, in Israel Specification 104,283 there is described and claimed an antiviral topical pharmaceutical composition for treating viral diseases of the skin or mucosa, comprising a poorly soluble antiviral nucleoside derivative dispersed in an aqueous gel carrier containing a gelling agent and a water-solubilized carboxylic or dicarboxylic acid salt. The teachings of said specification are incorporated herein by reference.
The invention described in said specification was based on the discovery that said formulation achieved better anti-viral effect than the ZoviraxR ointment or cream available on the market today.
After further research and development, however, it was surprisingly discovered that the composition described in said specification, in what was thought to be a placebo and in which the soluble anti-viral nucleoside derivative, i.e., acyclovir, was absent, also achieved better effect than the ZoviraxR ointment or cream available on the market today.
It has been concluded from the research performed with the nucleoside drug and with its absence that the antiviral effect of the composition is due to the enhanced penetration of the fatty acids as salts rather than free acids. The penetration of any antiviral agent is critical for the effective treatment of herpes virus, since the replication of the virus and the vesicles eruption occur deep in the basal epidermis (Stratum Granulosum).
Therefore, in light of this surprising discovery, the present invention relates to a topical pharmaceutical composition for the prevention and treatment of lesions and sores of the skin or mucosa associated with a herpes virus, comprising a salt of an unsaturated C.sub.14-18 fatty acid having 1-2 double bonds as active ingredient therein, in combination with a pharmaceutically or cosmetically acceptable carrier.